National Recovery Plan for the Basalt Peppercress Lepidium hyssopifolium Michelle Tumino Prepared by Michelle Tumino, Department of Sustainability and Environment, Victoria. Published by the Victorian Government Department of Sustainability and Environment (DSE) Melbourne, July 2010. © State of Victoria Department of Sustainability and Environment 2010 This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968. Authorised by the Victorian Government, 8 Nicholson Street, East Melbourne. ISBN 978-1-74242-063-9 This is a Recovery Plan prepared under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999, with the assistance of funding provided by the Australian Government. This Recovery Plan has been developed with the involvement and cooperation of a range of stakeholders, but individual stakeholders have not necessarily committed to undertaking specific actions. The attainment of objectives and the provision of funds may be subject to budgetary and other constraints affecting the parties involved. Proposed actions may be subject to modification over the life of the plan due to changes in knowledge. Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence that may arise from you relying on any information in this publication. An electronic version of this document is available on the Department of the Environment, Water, Heritage and the Arts website www.environment.gov.au For more information contact the DSE Customer Service Centre 136 186 Citation: Tumino, M. 2010. National Recovery Plan for the Basalt Peppercress Lepidium hyssopifolium. Department of Sustainability and Environment, Melbourne. 1 Contents Summary........................................................................................................... 3 Species Information......................................................................................... 3 Description 3 Taxonomy 3 Distribution 3 Population Information 4 Habitat 4 Decline and Threats ......................................................................................... 5 Recovery Information ...................................................................................... 7 Existing Conservation Measures 7 Recovery Objectives 7 Program Implementation and Evaluation 8 Recovery Actions and Performance Criteria 8 Biodiversity Benefits 9 Management Practices 9 Affected Interests 10 Role and Interests of Indigenous People 10 Social and Economic Impacts 10 Acknowledgments ......................................................................................... 10 References...................................................................................................... 10 Priority, Feasibility and Estimated Costs of Recovery Actions ................. 11 Figure 1. Former and current distribution of Basalt Peppercress ............................................... 4 Table 1. Population and threat information for the Basalt Peppercress...................................... 5 2 Summary The Basalt Peppercress Lepidium hyssopifolium is a small perennial herb endemic to south- eastern Australia, where it occurs in New South Wales, Victoria and Tasmania. There is little information on the previous distribution and abundance of the species, but its decline almost certainly relates to the widespread degradation and loss of grassland and grassy woodland habitats in south-eastern Australia. The Basalt Peppercress is currently known from about 35 populations containing about 1,700 plants. Current threats include grazing, competition and weed invasion, and habitat disturbance and destruction. The species is listed as Endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. This national Recovery Plan for the Basalt Peppercress is the first recovery plan for the species, and details its distribution, habitat, threats and recovery objectives and actions necessary to ensure its long-term survival. Species Information Description The Basalt Peppercress Lepidium hyssopifolium Desvaux is an erect, many-branched perennial herb growing to 1 m in height and belonging to the Family Brassicaceae. Basal leaves are toothed or pinnately lobed, with hairy, serrated margins. Stem leaves are linear-lanceolate, toothed or entire with hairy serrated margins, 1–4 cm long and 1–3 mm wide. The stems and stem leaves are covered with fine, short, erect hairs. Leaves have an ear-like lobe or appendage at their base. The inflorescence is borne on an elongated raceme, the flowers are tiny, greenish and inconspicuous, the sepals 0.8 mm long and petals reduced or absent. A distinguishing feature is the presence of two stamens. Silicula are elliptic to ovate, 3–5 mm long and 2–3 mm wide. Fruit are sometimes hairy with narrow wings and are borne on hairy, terete pedicels 3–5 mm long. The spreading fruit stalks are slightly curved, circular in cross section and covered with short hairs (description from Cropper 1993; Entwisle 1996). The Basalt Peppercress is a prolific seed producer and seed can remain viable in the soil for at least two years (possibly substantially longer), although the large seed size means dispersal away from the parent plant is limited (Cropper 1987, 1993). The species requires disturbance for seed germination and seedling recruitment (Cropper 1993). Taxonomy Prior to a review in 1982, the name Lepidium hyssopifolium was misapplied to three separate species: Lepidium africanum (an introduced weed species), Lepidium pseudohyssopifolium and Lepidium pseudotasmanicum. Lepidium hyssopifolium can be distinguished from similar native and introduced species by the presence of two stamens, some auriculate leaves, a lack of lobed or dissected upper stem leaves, and minute, soft, erect hairs on pedicels, fruits and stems. Lepidium hyssopifolium contains several segregates that are recognised but not described. The species is in the process of being redefined, and is likely to be split into several taxa (N. Scarlett pers. comm.1999). Until official determinations, classifications and identification keys have been prepared, all populations currently known as L. hyssopifolium are included here. Distribution The Basalt Peppercress is endemic to south-eastern Australia, where it is widely but patchily distributed from south-eastern New South Wales through Victoria to eastern Tasmania (Figure 1). In New South Wales the species is currently known from near Bathurst and Bungendore, in the South Eastern Highlands IBRA bioregion (sensu DEH 2000), and there is an old record from near Armidale in the New England Tablelands bioregion. In Victoria, the species occurs mostly west of Melbourne, in the Victorian Midlands and Victorian Volcanic Plain bioregions. In Tasmania, it is confined to the east of the State, in the Tasmanian South East, Tasmanian Northern Midlands, Ben Lomond and Flinders bioregions, and formerly occurred in the Freycinet and Tasmanian Midlands bioregions. Maps showing the distribution of the Basalt Peppercress are available from each State nature conservation agency. 3 Former distribution Current distribution Known Former Occurrences Present Occurrences Figure 1. Former and current distribution of Basalt Peppercress Population Information The Basalt Peppercress is currently known from about 35 populations containing about 1,700 plants (Table 1), most of which occur in Tasmania. There are three populations containing about 40 plants in New South Wales and seven populations containing about 500 plants in Victoria. There are about 27 populations in Tasmania containing about 1,200 plants, distributed across the east of the State. The largest populations are at Tunbridge (~500 plants), Wyldes Plain (~200 plants) and Oatlands (~130 plants), while most other sites have fewer than 40 plants (DPIWE 2003). Adequate site information for most of the Tasmanian populations was unavailable and hence determination of the most important populations in Tasmania will be actioned through this Recovery Plan. Habitat The original habitat in which the Basalt Peppercress occurred is not precisely known, but was probably eucalypt and/or Allocasuarina woodland with a grassy understorey, and native temperate grasslands (Leigh et al. 1984). Almost all remaining populations of Basalt Peppercress occur in heavily modified, non-natural environments, usually amongst exotic pasture grasses and weed species, sometimes with an overstorey of introduced tree species. Soils are light to heavy, often friable, clay loams. Most sites are on roadsides, on fringes of developed agricultural land or occur in small reserves within an agricultural landscape. The population at Tunbridge (TAS) occurs at a site with reasonable native vegetation cover, in this case Eucalyptus amygdalina and Acacia mearnsii woodland (Kirkpatrick & Gilfedder 1998), while the Gib TSR site (NSW), despite a long history of periodic disturbance, still has a floristically diverse native grassland. Microsite conditions appear to be important for the establishment and persistence of Basalt Peppercress. Plants appear to establish on relatively open bare ground where there is limited competition from other plants (both native and introduced species), rather than in areas with 4 thick ground cover.